we've been working on gelatin microfluidics using 3D printing at Symbiolab/IRNAS and got some good results by modifying the FRESH method by Hinton et al., 2015 (http://advances.sciencemag.org/content/1/9/e1500758.full). There's more info and a video here: http://irnas.eu/bio-lab-symbiolab/2017/08/07/freeform-gelatin-microfluidics . Also, we're preparing the release of our open-source 3D bioprinting platform, (including methods) so you can already find the documentation of the protocol on Github: https://github.com/symbiolab/Vitaprint_methods/tree/master/Gelatin%20Microfluidics

Hope you find it useful. Also, feedback would be much appreciated!All the best from the sunny side of the Alps, :)